code: def mse_loss(input, target):
      return torch.sum((input - target) ** 2) / input.data.nelement()
  
file_path: gans-with-pytorch/ralsgan/ralsgan.py
imports: import argparse
  import numpy
  import torch
  from torch import nn, optim
  from torch.autograd.variable import Variable
  from torchvision import transforms, datasets
  import os
label_desc: Use image node_id 3 for calling a global function with example usage: mse_loss(input, target) and returns: unknown